CRM-12884: First run at Manage Volunteers tab. Includes help template and post-processing logic.
Merge pull request #13 from fjg-conflux/CRM-12884-1

CRM-12884: First run at Manage Volunteers tab.

Frank - replace the 'magical' use of visibility_id = 1 with something like this:
$publicVisibiltyId = CRM_Core_OptionGroup::getValue('visibility', 'public', 'name'));